Herpes Simplex Virus 1 Immunoglobulin G (IgG) Antibody

What Does This Test Measure?

IgG antibodies are a type of protein your immune system creates to protect against infections. This test detects whether you have developed immunity to HSV-1, which can remain in your body long after the initial infection. Unlike IgM antibodies, which appear early in an infection, IgG antibodies typically develop later and persist for years.

Why Might You Need This Test?

Doctors may order this test if you have symptoms of HSV-1 infection (like cold sores), if you’ve been exposed to someone with HSV-1, or if you’re planning pregnancy and want to assess your immune response to past infections. It can also help confirm a diagnosis when other tests are inconclusive.

How Is the Test Performed?

A blood sample is taken from a vein in your arm. The sample is sent to a lab, where it is analyzed using an immunoassay method to detect HSV-1 IgG antibodies. Results are reported as positive or negative, with no specific numeric reference range provided.

What Do the Results Mean?

A positive result means your body has produced IgG antibodies against HSV-1, indicating past exposure and immunity. A negative result suggests you either haven’t been exposed or your immune system hasn’t yet produced detectable antibodies. This does not rule out current infection—other tests may be needed for active infection diagnosis.